My autotrail tracker has an end bed under which is the combi heating system and hot air pipework and ducting. After the heating had been on a while I happened to lift the bed up to access the storage underneath and was met with a blast of hot air. There are no leaks or anything. It's just the heat on the case of the heater and pipe ducts that builds up. I was wondering if anyone had fitted a 12v extractor fan to blow this wasted hot air into the habitation area. Thanks.